Biting and hitting how to get him to stop??

[emomother3]

I have 3 children two of which are 3 and 1.my oldest has a problem with biting and putting his hands on his little brother when i leave them in there room to play. I dont understand why all the sudden why he has started doing it but its getting worse and worse. i have found bite marks on my 1 year old and marks from where he has pinched him. I have tried smacking his butt and trying to explain hes not allowed to hurt his brother. i have also tried time outs and nothing seems to make him stop. what should i do ? any advice will help because nothing is working.                                  

 

[goddess99]

I've done the ~ you bite and I'll bite you back. works